HYDRAULIC SYSTEM FUNCTIONAL TEST

TM 55-4920-426-13&P

2-8

HYDRAULIC SYSTEM FUNCTIONAL TEST

Start engine using procedures in Para 2-3, Steps A thru N.

Release the locknut located below the adjusting screw on the system relief valve. Turn the system

relief valve adjusting screw counterclockwise, three times.

Set the LP Gage shutoff valve to main pump inlet.

Turn the fluid volume control counterclockwise to maximum output. Flowmeter should indicate 10 GPM

or more.

Read pressure on compound GAGE. Reading should be between 30 and 40 psi. If pressure is not

within the range, remove the cap on the low pressure relief valve. Back off the locknut. Turn the adjust-

ment screw (clockwise = increase, counterclockwise = decrease) until desired pressure range is obtain-

ed. Tighten locknut and install cap.

Close the compensator shut off valve, turn knob clockwise.

Adjust the fluid volume control to 2 GPM.

Turn the flow control valve to the supply port position.

Always set the high pressure relief valve at a higher pressure (150

psi higher) than the pump compensator pressure. DO NOT use relief

valve to regulate the test stand output pressure.

Adjust the system relief valve to relieve the system pressure at 3150 psi. Turn the system relief valve

adjusting screw clockwise until 3150 psi indicates on the system pressure gage. Lock the adjustment

screw with the locknut.

Open the compensator shut off valve, turn knob counterclockwise. Adjust the system pressure with the

pressure compensator until the system pressure gage indicates a pressure of 3000 PSI. Lock control

with locknut under knob.

Return the flow control valve to the BY-PASS position.

Increase the volume flow to 10 GPM.

Check the hydraulic fluid temperature gage for proper operating range. Check overall system for leaks.

Close the compensator shut off valve .

Decrease the fluid flow to 2 GPM.

Turn the flow control valve to the SUPPLY PORT position.

2-21